Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
74 Cards in this Set
- Front
- Back
Plant growth requires _____ elements
|
16
|
|
Elements required in amounts above 0.5% of the plant's dry weight
|
Macronutrients
|
|
These elements make up traces of the plant body
|
Micronutrients
|
|
Carbon, oxygen and hydrogen are obtained from?
|
Air and water
|
|
Other nutrients are taken up by _____ as minerals dissolved in soil water
|
roots
|
|
Consists of particles from weathered rocks, mixed with decomposing organic matierial
|
Soil
|
|
Decomposing organic material
|
Humus
|
|
These have the best oxygen and water penetration and roughly equal amounts of sand, silt, and clay
|
Loams
|
|
Contains the greatest amount of organic matter, so the roots of most plants grow deeply here
|
Topsoil
|
|
Another name for topsoil
|
A horizon
|
|
Carries away soil nutrients
|
Leaching
|
|
____ is fastest in sandy soils, which don't bind nutrients as well as clay soils
|
Leaching
|
|
Strong winds, fast-moving water, sparse vegetation, poor farming is all ...
|
soil erosion
|
|
This is greatest in areas where water and nutrient concentrations best match the plant's requirements
|
root growth
|
|
Root specializations such as _____,_____, and ____ help plants absorb water and nutrients
|
Hairs, mycorrhizae, nodules
|
|
Water moves from soil through a roots......?... to the vasuclar cylidner
|
A root's epidermis and cortex
|
|
___ distributes water and mineral ions to the rest of the plant
|
Xylem
|
|
Thin extensions of root epidermal cells
|
Root hairs
|
|
Increase surface area of root and allow it to absorb water and nutrients
|
Root hairs
|
|
____ enters plant cells by moving through the cytoplasm or by diffusing through cell walls
|
water
|
|
Mineral ions only enter cytoplasm through ____ _____ in the plasma membranes
|
active transporters
|
|
Once incytoplasm, water and ions diffuse cell to cell through _____ until they enter xylem in the vascular cylinder
|
plasmodesmata
|
|
cell junctions that connect the cytoplasm of adjacent plantcells
|
plasmodesmata
|
|
Soil water can only enter the ____ ____ by passing through an endoderal cell
|
vascular cylinder
|
|
The endodermal cell is protected by a waterproof ...
|
Casparian strip
|
|
The vasuclar cylinder is layered by what?
|
The pericycle and the endodermis
|
|
__ ____ in the cell's plasma membranes control the movement of mineral ions from soil water into the plant body
|
Transport proteins
|
|
Waxy, waterproof band between the plasma membranes of root endodermal cells; seals abutting cell walls
|
Casparian strip
|
|
Fungi called _____ grow in/around plant roots to help them absorb mineral ions from a larger volume of soil than roots alone
|
mycorrihaze
|
|
Mutually beneficial fungus-plant root partnership
|
Mycorrhiza
|
|
Mycorrhiza gets some ____ & ____-_ ____ _____ and the plant receives minerals the fungus can better absorb
|
sugars and nitrogen-rich compounds
|
|
____ ______ in root nodules shares their fixed nitrogen with certain plants (clovers,peas, legumes)
|
Anaerobic bacteria
|
|
Swellings of some plant roots that contain nitrogen-fixing bacteria
|
Root nodules
|
|
These form root nodules on clovers, peas, and other legumes
|
Nitrogen-fixing bacteria
|
|
Atmospheric nitrogen is _______
|
N=_N
|
|
A bacterial enzyme uses ATP to convert nitrogen gas to ammonia
|
nitrogen fixation
|
|
What two features of water drive its movement in vascular plants?
|
Evaporation and Cohesion
|
|
From leaves and stems, drives the upward movement of water through xylem inside a vascular plant
|
Evaporation
|
|
Water's this allows it to be pulled from roots into all other parts of the plant
|
Cohesion
|
|
How transpiration creates a tension that pulls a cohesive column of water through xylem, from roots to shoots (straw)
|
Cohesion-tension theory
|
|
Evaporation of water from plant parts
|
transpiration
|
|
Water is pulled upward from roots through continuous pipelines of xylem by the negative pressure (____) of evaporation (_____) and ______ among water molecules
|
tension, transpiration, cohesion
|
|
At least 90% of water taken up by roots is lost through...
|
evaporation
|
|
Plants must conserve water for _____, ____, ____ ____...
|
Photosynthesis, growth, membrane functions
|
|
A ____ & ____ restrict the amount of water vapor that diffuses out of the plant's surfaces- but also restrict access to CO2 for photosynthesis, and oxygen for aerobic respiration
|
Cuticle and stomata
|
|
The cuticle is _____, so it does not prevent light from reaching photosynthetic tissues
|
Traslucent
|
|
pair of cells that define a stoma across the epidermis of a leaf or stem
|
guard cell
|
|
When guard cells swell with water a gap (____) forms between them
|
stoma
|
|
When guard cells lose water, the gap ____
|
closes
|
|
What affects whether stomata open or close?
|
The level of Co2 in the leaf, water availability, and light intensity
|
|
Stomata close in response to____ in polluted air
|
chemicals
|
|
Closure protects the plant from chemicals but also does what?
|
Prevents uptake of CO2 for photosynthesis, and stops growth
|
|
Distributes the organic products of photosynthesis through plants
|
phloem
|
|
vasuclar tissue with organized arrays of conducting tubes, fibers, and strands of parenchyma cells
|
Phloem
|
|
Dead and mature, function as pipes through which water travels
|
xylem
|
|
Still alive
|
phloem
|
|
Sugar-conducting tubes of the phloem and consist of living cells
|
Sieve tubes
|
|
Actively transport the organic products of photosynthesis (sugars) into sieve tubes
|
Companion cells
|
|
Sugar travels through sieve tubes to parts of the plant, where it is broken down for ...
|
energy, remade into other compounds, or stored
|
|
Movement of sugars through the phloem
|
translocation
|
|
Plants store their carbs as ____
|
starch
|
|
This is too big to transport across plasma membranes, so plant cells break it down into sucrose
|
Starch
|
|
Main carbohydrate transported through the phloem
|
sucrose
|
|
Organic compounds flow from a ____ to a _____
|
source to a sink
|
|
Region where companion cells load molecules into sieve tubes
|
source
|
|
Region here molecules are being used or stored
|
sink
|
|
A plant's main source region
|
photosynthetic tissues
|
|
These are sinks...
|
roots and fruits
|
|
A ____ _____ drives the movement of fluid in phloem
|
pressure gradient
|
|
explanation for how flow of fluid through phloem is driven by differences in pressure and sugar concentration between a source and a sink
|
Pressure flow theory
|
|
What is the first step of Pressure Flow Theory?
|
1. Companion cells load sugar into sieve tubes by active transport
|
|
What is the second step of Pressure Flow Theory?
|
Solute concentration in sieve tubes increases. Water moves in by osmosis. The increased fluid increases pressure
|
|
What is the third step to Pressure Flow Theory?
|
The high pressure pushes fluid from source to sink regions, where pressure and solute concentrations decrease
|
|
What is the final step to Pressure Flow Theory?
|
Sugars are unloaded at sink regions; water follows by osmosis
|